Preparation of self-filtering ground coffee



Patented Oct. 25, 1938 PATENT FFlE 2,134,276 PREPARATION OF sELr-m'mnm GROUND COFFEE Arthur Boscher and Franz von Herrenburger, Dresden, Germany, assignors to the firm R. Seelig & Hille, Dresden, Germany No Drawing. Application April I, 1937, Serial No. 135,530. In Germany May 14, 1936 Claims.

This invention relates to a process of preparing ground coffee that is self-filtering and ready for infusion in bags having relatively large pores.

The invention attains its object by first sepa- 5 rating the coarsely granular portion of ground coffee from the mealy portion thereof and then adding to each portion a bassorin-containing gum, such as cherry or tragacanth gum, com-' bined with a sugar solution. To eifect granula- 10 tion of the mealy portion a larger amount of gumis added thereto than to the granular portion. Both portions are then mixed.

'It is known to treat the mealy portion of ground roasted coffee after its separation from the coarse-grained portion with a gum solution containing for instance sugar, gum arabic or acacia gum. These substances are, however, soluble in water, but bassorin-containing gum added to the ground cofiee according to the invention swells up in water and thus renders it self-filtering, whilst in accordance with the known processes it is desirable to bring the coflee dust into the infusion.

Although it is known to use tragacanth gum I in the production of candy and lozenges as granulating substance in combination with coffee meal, this gum has not been employed hitherto for the purpose of preparing coflee ready for infusion. It was not obvious to apply the water insoluble substance used for the known purposes stated to ground coifee in order to influence the filtrability thereof in so favorable a manner that the extracting property is unimpaired and the fine particles of the ground coflee are retained .35 in the filtering bag.

The effect attained is'all the more surprising as just in coffee treatment great eflorts are made to emulsify the insoluble coffee particles in the infusion with the aid of gum-like vegetable 40 products.

The following proportional amounts have for instance been found to give favorable results:

Example To 100 parts by weight oi, ground coilee that fusion bags having large perforations.

is either pure or contains permissible flavoring matter 2.5 parts by weight of a per cent. sugar solution and 2 parts by weight of a 5 per cent. bassorin-containing gum solution are added.-

Owing to this addition, the ground coflfee is 5 coated with a thin preserving fllm which closes the pores of the coffee particles, granulates the mealy matter and prevents evaporation of thearomatic substances.

The addition of gum and sugar, on coming in 10 contact with boiling water duringinfusion, renders the c'oifee self-filtering, binds the developing slime and owing to its colloidal action retains it in the bag or strainer. I

The process according to the invention is. of 15 course applicable also to coifee substitutes, made from barley, malt, etc.

We claim:- a

1. Process for preparing infusible self-filtering 2o coffee, which consists of the step of treating ground coflee with a water insoluble, sugary and bassorin-co'ntaining solution of gum.

2. Process according to claim 1, in which the coarse-grained and the mealy portions oiground coifee are subjected to separate treatment and are thereafter mixed. 3.Processa.ccordingtoclaim ,consistingin adding to 100 parts by weight ofgground cofllee 2.5 parts by weight of a 50 per cent. sugar solu- 30 tion and 2 parts by weight oi/a 5 per cent. bassorin-containing gum'solution.

4. Process according to claim 1, consisting in adding to 100-parts by weight of ground coiiee mixed with permissible flavoring matter 25 parts by weight of a.50 per cent. sugar solution and 2 partsby weight of a 5 percent. 'bassorincontaining gum solution.

5.Processaccordingtoclaim1,inwhichthe ground coffee after treatment is placedinin-Q 

